echo

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world, fully covering the safety profile. The description adds no behavioral context beyond confirming it returns the input, so it contributes little value on top of the structured data.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single short sentence with no filler and the core behavior front-loaded. It is appropriately sized for a trivial tool, though it is so sparse that it borders on under-specification.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a trivial echo utility, the description plus rich annotations, full schema coverage, and an output schema cover essentially everything an agent needs. Only the absence of stated use-cases keeps it from being fully complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With a single parameter and 100% schema description coverage, the schema already documents 'message'. The description adds nothing about format, limits, or handling beyond what the schema provides, so the baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

"Echoes back the input message" is a clear verb+resource and matches the tool's behavior, but the name 'echo' already conveys the same thing, making the description largely a restatement. It does not distinguish this utility tool from the many database-oriented siblings.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no indication of when to use this tool, when not to, or what alternatives exist. Given it sits among database/query tools, some guidance on its test/utility role would be valuable but is entirely absent.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.